CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/389,776, filed on Oct. 5, 2010. The entire disclosure of the above application is incorporated herein by reference.

FIELD

The present disclosure generally relates to fluid pumps. More particularly, a pump having a first outlet providing a high fluid flow at low pressure and a second outlet providing low fluid flow at high pressure is described.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.

In typical present day automotive applications, manufacturers may utilize two separate fluid pumps associated with an automatic transmission. A first fluid pump provides a high fluid flow at a relatively low pressure to cool and lubricate the components of the automatic transmission. A second transmission fluid pump is configured to provide a high output pressure at a relatively low flow rate to control transmission operation.

More particularly, the high pressurized fluid is selectively placed in communication with one or more chambers such that a force may be applied to various clutches, brakes or other actuators to control transmission operation. While the separate pumps may have functioned satisfactorily in the past, it may be desirable to provide a pump including dual outlets providing the functions of both pumps in a single unit having a reduced size, cost and weight when compared to previous systems.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

A dual outlet pressure pump includes a housing having first and second inlets as well as first and second outlets. A plurality of vanes are driven by a rotor. An asymmetric rotor cavity includes a first surface engaged by the vanes shaped to at least partially define a plurality of low pressure, high volume chambers. The cavity also includes a second surface engaged by the vanes shaped to at least partially define a plurality of high pressure, low volume chambers. Rotation of the rotor and vanes substantially simultaneously pumps a high volume of low pressure fluid between the first inlet and the first outlet and a low volume of high pressure fluid between the second inlet and the second outlet.

A fluid pump includes a housing having an inlet, a first outlet and a second outlet. A plurality of vanes are driven by a rotor rotatably supported in the housing. The vanes define pressure chambers having different volumes. The first and second outlets receive fluid from the inlet and are associated with chambers having a decreasing volume. The second outlet supplies fluid at a higher pressure and a lower flow rate than the first outlet.

Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1 is a perspective view of a dual outlet pump constructed in accordance with the teachings of the present disclosure;

FIG. 2 is a partial exploded perspective view of the pump shown in FIG. 1;

FIG. 3 is a fragmentary view of a portion of the dual outlet pump;

FIG. 4 is a perspective view of a front plate of the dual outlet pump;

FIG. 5 is a rear view of the dual outlet pump;

FIGS. 6-9 are cross-sectional side views taken at different planes;

FIG. 10 is a cross-sectional side view of an alternate dual outlet pump;

FIG. 11 is a cross-sectional view taken through the pump depicted in FIG. 10;

FIG. 12 is another cross-sectional view of the dual outlet pump taken at a different plane;

FIG. 13 is another cross-sectional view of the dual outlet pump taken at a different plane;

FIG. 14 is a cross-sectional side view of the dual outlet pump;

FIG. 15 is a perspective view of a rear plate;

FIG. 16 is another perspective view of the rear plate;

FIG. 17 is a perspective view of a front plate;

FIG. 18 is another perspective view of the front plate;

FIG. 19 is a perspective view of a mid-plate;

FIG. 20 is a fragmentary perspective view of another alternate dual outlet pump; and

FIG. 21 is a cross-sectional view of the dual outlet pump and motor assembly.

Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings.

FIGS. 1-6 relate to a dual outlet pump 10 including a front plate 20, a mid-plate 22 and a rear plate 24 fixed to one another by a plurality of threaded fasteners 26. As shown in FIG. 6, fastener 26 is configured as a socket head shoulder bolt to assure a predetermined spacing between front plate 20 and rear plate 24. A driveshaft 14 is fixed for rotation with a rotor 28 that rotates relative to front plate 20, mid-plate 22 and rear plate 24. Front plate 20, mid-plate 22 and rear plate 24 are adapted to be positioned within a housing (not shown) having a cylindrical cavity. Rotation of driveshaft 14 causes a pumping of fluid from an inlet port 15 to a first outlet port 16, as well as a second outlet port 18. First outlet port 16 provides a high flow, low pressure output. Second outlet port 18 provides a low flow, high pressure output.

Pump 10 also includes a plurality of radially moveable vanes 32 positioned within a plurality of radially extending slots 34 formed in rotor 28. A distal surface 36 of each vane 32 is in contact with an inner surface 38 of mid-plate 22. Inner surface 38 is substantially cylindrically shaped having its center positioned at an eccentric location relative to a rotor axis of rotation 42. Shaft 14 also rotates along axis of rotation 42. The eccentric relationship between surface 38 and axis of rotation 42 defines a plurality of sequentially increasing and then decreasing chambers 46 between adjacent vanes 32. First outlet port 16 is shaped and positioned to be in fluid communication with chambers 46 having a relatively large volume but decreasing in size such that a relatively high flow rate of pressurized fluid exits first outlet port 16. Further along the circumference in the direction of decreasingly sized chambers, high pressure second outlet port 18 is positioned in communication with chambers 46 where a very minimal clearance exists between surface 38 of mid-plate 22 and an outer surface 50 of rotor 28. The size of pressure chambers 46 at this circumferential location is relatively small thereby producing a relatively high pressure, low flow through second outlet port 18.

A plurality of circumferentially spaced apart passageways 52 are provided in fluid communication with a proximal face 54 of each vane 32. Passageways 52 are provided with pressurized fluid from one of low pressure outlet port 16 or high pressure outlet port 18. Rear plate 24 includes a first groove 58 in communication with some of the passageways 52 and low pressure outlet port 16. A passageway 59 interconnects groove 58 and first outlet port 16. A second circumferentially extending groove 60 is in fluid communication with the remaining passageways 52 and high pressure outlet port 18. A passageway 61 interconnects groove 60 and high pressure outlet port 18. Front plate 20 also includes similar first and second grooves 64, 66. Unlike typical vane pumps, the dual outlet pump 10 of the present disclosure is unbalanced due to a provision of high pressure and low pressure outlet ports. In an attempt to balance the loads through pump 10, the circumferential extent of grooves 58, 64 is substantially greater than the circumferential extent of grooves 60, 66.

Front plate 20 includes an inlet port groove 68 in fluid communication with inlet port 15 and several chambers 46 having sequentially increasing volumes. A similar inlet port groove 69 is provided on rear plate 24. A low pressure outlet groove 70 circumferentially extends along a mating face 72 in communication with several chambers 46 having subsequently decreasing volumes. Rear plate 24 also includes a corresponding low pressure outlet groove 73. A passageway 76 extends through front plate 20 exiting the side of the plate to provide low pressure fluid between a first o-ring 80 and a second o-ring 82. A third o-ring 84 is positioned on rear plate 24. O-rings 80, 82, 84 sealingly engage an inner cylindrical of the housing not depicted in the drawings. Low pressure fluid is provided between seals 80, 82 to enhance their sealing properties.

Front plate 20 also includes a high pressure outlet aperture 85 in fluid communication with second groove 66. Mid-plate 22 includes a notch 90 for providing high pressure fluid in communication with second outlet port 18.

FIGS. 10-19 depict a second dual outlet pump identified at reference numeral 200. Pump 200 includes a housing 202, a front plate 204, a mid-plate 206, and a rear plate 208. Fasteners 210 interconnect front plate 204, mid-plate 206 and rear plate 208. Fasteners 207 fix a flange 209 of front plate 204 to housing 202. A shaft 212 is fixed for rotation with a rotor 214. A plurality of radially moveable vanes 216 are positioned within slots 218 formed in rotor 214. Pressure chambers 215 are defined between adjacent vanes 216, rotor 214 and mid-plate 206. Driveshaft 212 rotates about an axis of rotation 217. Bearings 219, 220 rotatably support driveshaft 212. A lip seal 221 is positioned within front plate 204 and sealingly engages driveshaft 212.

Housing 202 includes a low pressure inlet 222, a high pressure inlet 224, a low pressure outlet 226 and a high pressure outlet 228. Mid-plate 206 includes an asymmetrical cavity 232 providing pump 200 with its dual output pressure characteristic. A first portion 236 of asymmetrical cavity 232 is defined by a first surface 238 and is spaced from an outer surface 240 of rotor 214 a maximum distance. As such, the volumes defined by pressurized chambers located between adjacent vanes 216 and first surface 238 are relatively large when compared to other pressurized chambers about the circumference of rotor 214. More particularly, a second surface 246 defines a second portion 248 of asymmetric cavity 232. Second surface 246 is positioned much closer to outer surface 240 of rotor 214 than first surface 238. To provide pumping, it should be appreciated that both first surface 238 and second surface 246 are curved surfaces such that successive pressurized chambers of increasing volume and then decreasing volume are defined when the rotation direction of rotor 214 is taken into account.

As shown in the Figures, high pressure inlet 224 is associated with the increasing volume chambers at least partially defined by surface 246. A high pressure inlet port 249 is formed in front plate 204. A high pressure inlet port 250 is formed in rear plate 208. The high pressure inlet ports 249, 250 are aligned with a high pressure inlet aperture 251 extending through mid-plate 206.

High pressure outlet 228 is in fluid communication with the pressure chambers 215 having sequentially decreasing volumes at least partially defined by surface 246. Pressurized fluid exits pressure chambers 215 through high pressure outlet ports 253, 255 in front plate 204 and rear plate 208, respectively. A high pressure outlet aperture 257 interconnects high pressure outlet ports 253, 255.

Low pressure inlet 222 is in fluid communication with a cavity 252 formed between an inner surface 254 of housing 202 and an outer surface 258 of mid-plate 206. As shown in FIGS. 14 and 19, a chamfer 260 is formed on mid-plate 206 to provide a low pressure inlet passageway 261 for fluid passing through low pressure inlet 222 to enter the chambers at least partially defined by first surface 238. Low pressure inlet ports 262, 264 are formed in front plate 204 and rear plate 208, respectively. Low pressure inlet ports 262, 264 provide a reservoir and passageway for low pressure fluid to enter the chambers having sequentially increasing volume associated with first surface 238. As rotor 214 rotates, pressurized fluid enters low pressure outlet ports 270, 272. A low pressure outlet aperture 276 extends through mid-plate 206 and interconnects low pressure outlet ports 270, 272. The high pressure fluid path remains separated from the low pressure fluid path.

Rotor 214 includes a plurality of passageways 292 positioned at the ends of slots 218. Front plate 204 includes a first circumferentially extending slot 294 in communication with the low pressure fluid and an opposing circumferentially extending slot 296 in receipt of high pressure fluid. In similar fashion, rear plate 208 includes a first slot 300 in receipt of low pressure fluid and a second slot 302 in receipt of high pressure fluid. The size and shape of each of the slots corresponds to the positions of passageways 292 to apply pressurized fluid to a back face of vanes 216 to maintain engagement between each vane and first surface 238 and second surface 246.

FIG. 20 depicts an alternate dual outlet pump 320. Pump 320 is substantially similar to pump 200. As such, like elements will retain their previously introduced reference numerals including a lower â€œaâ€ suffix. FIG. 20 represents a possible orientation of mid-plate 206a having low pressure inlet passageway 261a positioned on an opposite side of the pump as low pressure inlet 222a. It is contemplated that the pump 320 is mounted vertically as depicted in FIG. 20. The cavity 252a between outer surface 258a and inner surface 254a may become filled with fluid due to the position of pump 320 within a reservoir or some other fluid supply mechanism. The fluid to be pumped continues to fill cavity 252a until it reaches and enters low pressure inlet passageway 261a. As such, a particular customer's packaging requirements regarding the location of plumbing inlets and outlets may be met using this concept.

FIG. 21 represents an exemplary motor and pump assembly 350 including a motor 352 driving a shaft 354. Shaft 354 is a monolithic, one-piece member extending through a mounting plate 356. Shaft 354 is fixed for rotation with a rotor 358 of a pump 360. Pump 360 may be configured as pump 10, pump 200 or pump 320 without departing from the scope of the present disclosure.

The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.